A friend by definition is someone you know well and regard with affection and trust.
I am not a very outgoing person, and to be totally honest, I am very isolated from other human beings. Except for my family and people at school. I cannot say who I would like to have as friend. I never given much thought. Perhaps I like God to be my friend. He is not selfish and very forgiving. He knows the hearts, seeing you for you; the imperfections, the motives, the joys and virtues. I could say what qualities a friend should have. A friend is loyal, reliable, trustworthy, and loving.
The friend is loyal by sticking by you through good times and bad times. She would not gossip behind your back, spilling intimate details of your life. She would try to defend you and praise you. You can always rely on her to do the right thing, to be there when it’s needed. (I am using female terms, because I am a girl, but God is not.)
She has your trust. Trust to share secrets, trust to tell on you if you got a problem, and trust to be honest when asking her opinion about anything.
And she is loving. A friend is someone sticking closer to you than a sibling. She loves you. And you love her. You two are close as siblings. She knows everything about you. Likewise, you know everything about her. They are like family. You would have no problem if they spent the night...